A089217 n-2 is a prime of the form 4*k+3.

5, 9, 13, 21, 25, 33, 45, 49, 61, 69, 73, 81, 85, 105, 109, 129, 133, 141, 153, 165, 169, 181, 193, 201, 213, 225, 229, 241, 253, 265, 273, 285, 309, 313, 333, 349, 361, 369, 381, 385, 421, 433, 441, 445, 465, 469, 481, 489, 493, 501, 505, 525, 549, 565, 573

Offset: 1

Author

Giovanni Teofilatto, Dec 10 2003

Keywords

• easy
• nonn

References

• M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988.
• Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997.

Crossrefs

Cf. A087915, A089193.

Programs

Mathematica

Select[4*Range[0,200]+3,PrimeQ]+2 (* Harvey P. Dale, Jun 04 2017 *)

Formula

a(n) = A087915(n)+ A089193(n)

Extensions

Offset corrected by Arkadiusz Wesolowski, Aug 09 2011

Corrected and extended by Harvey P. Dale, Jun 04 2017